How much time do you spend online each week? If you're an average Net user, a new poll shows, it's around 13 hours--excluding e-mail.

The Harris Interactive poll, released Wednesday, found that 80 percent of U.S. adults go online, whether at home, work, or elsewhere. Those who surf the Net spend an average of 13 hours per week online, but that figure varies widely. Twenty percent are online for two hours or less a week, while 14 percent are there for 24 hours or more.

The average number of hours that people spend online each week has grown over the years, hovering at 7 hours from 1999 through 2002, 8 or 9 hours from 2003 through 2006, and 11 hours in 2007. The level hit its peak at 14 hours in October 2008--after the global recession had set in and just before the U.S. presidential election.

The jump in time spent in cyberspace likely stems from a few factors, according to Harris. More people are comfortable using the Internet. More of them are shopping and watching TV online. In addition, the number of Web sites and online applications has increased. Harris adds that the recession may also play a role since surfing the Net at home is free (after paying monthly access fees), while going out means spending money.

The age group that spent the most time online per week: 30- to 39-year-olds, at 18 hours.

The total number of U.S. adults on the Internet is 184 million, around 80 percent of the total population, according to the poll. That figure is virtually the same as in 2008 but is a big jump from 1999, when it reached at 56 percent, and from 1995, when the figure was a mere 9 percent.

The number of people who surf the Net at home rose to 76 percent this year, compared with 66 percent in 2005, 46 percent in 1999, and 16 percent in 1996. In 1995, that specific question wasn't even asked.

About the author

Journalist, software trainer, and Web developer Lance Whitney writes columns and reviews for CNET, Computer Shopper, Microsoft TechNet, and other technology sites. His first book, "Windows 8 Five Minutes at a Time," was published by Wiley & Sons in November 2012.
See full bio